Display screen or portion thereof with a graphical user interface



FIG. 1 is a front view of a display screen or portion thereof with a graphical user interface, shown in the environment of a tablet;

FIG. 2 is a perspective view thereof;

FIG. 3 is a front view of a display screen or portion thereof with a graphical user interface, shown in the environment of a monitor; and,

FIG. 4 is perspective view thereof.

The broken line showing of a display screen with graphical user interface is included for the purpose of illustrating portions of the article and forms no part of the claimed design. The broken line showing of a tablet and monitor is included for the purpose of illustrating environmental structure and forms no part of the claimed design. 

CLAIM The ornamental design for a display screen or portion thereof with a graphical user interface, as shown and described. 